BLUE 220; 3-(4-Diethylamino-2-methylphenyl)-3-(1-ethyl-2-methyl-1H-indol-3-yl)-4-azaphthalide; 3-[4-(Diethylamino)-2-methylphenyl]-3-(1-ethyl-2-methyl-1H-indole-3-yl)-4-azaphthalide; 7-[4-(Diethylamino)-2-methylphenyl]-7-(1-ethyl-2-methyl-1H-indol-3-yl)furo[3,4-b]pyridin-5(7H)-one